Channel Capacity Limits of Cognitive Radio in Asymmetric Fading Environments

Abstract

Cognitive radio technology is an innovative radio design concept which aims to increase spectrum utilization by exploiting unused spectrum in dynamically changing environments. By extending previous results, we investigate the capacity gains achievable with this dynamic spectrum approach in asymmetric fading channels. More specifically, we allow the secondary-to-primary and secondary-to-secondary user channels to undergo Rayleigh or Rician fading, with arbitrary link power. In order to compute the capacity, we derive the distributions of ratios of Rayleigh and Rician variables. Compared to the symmetric fading scenario, our results indicate several interesting features of the capacity behaviour under both average and peak received power constraints. Finally, the impact of multiple primary users on the capacity under asymmetric fading has also been studied.

6 pages, 8 figures, in Proceedings of IEEE International Conference on Communications (ICC 2008), Beijing, China, May 19-23, 2008

Cited by in corpus (4)

• The Effects of Limited Channel Knowledge on Cognitive Radio System Capacity
• On the Statistics of Cognitive Radio Capacity in Shadowing and Fast Fading Environments (Journal Version)
• On the Performance Analysis of Underlay Cognitive Radio Systems: A Deployment Perspective
• Performance Analysis of Mean Value-Based Power Allocation with Primary User Interference in Spectrum Sharing Systems